From: Kees Cook keescook@chromium.org
[ Upstream commit 311fb40aa0569abacc430b0d66ee41470803111f ]
Clean up uses of "(size_t)-1" in favor of SIZE_MAX.
Cc: linux-hardening@vger.kernel.org Suggested-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Kees Cook keescook@chromium.org Stable-dep-of: e9a40e1585d7 ("fortify: Do not cast to "unsigned char"") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/fortify-string.h | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-)
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h index fce2fb2fc962..ae076aae9e66 100644 --- a/include/linux/fortify-string.h +++ b/include/linux/fortify-string.h @@ -3,6 +3,7 @@ #define _LINUX_FORTIFY_STRING_H_
#include <linux/const.h> +#include <linux/limits.h>
#define __FORTIFY_INLINE extern __always_inline __gnu_inline __overloadable #define __RENAME(x) __asm__(#x) @@ -17,9 +18,9 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning(" #define __compiletime_strlen(p) \ ({ \ unsigned char *__p = (unsigned char *)(p); \ - size_t __ret = (size_t)-1; \ + size_t __ret = SIZE_MAX; \ size_t __p_size = __builtin_object_size(p, 1); \ - if (__p_size != (size_t)-1 && \ + if (__p_size != SIZE_MAX && \ __builtin_constant_p(*__p)) { \ size_t __p_len = __p_size - 1; \ if (__builtin_constant_p(__p[__p_len]) && \ @@ -95,7 +96,7 @@ char *strcat(char * const POS p, const char *q) { size_t p_size = __builtin_object_size(p, 1);
- if (p_size == (size_t)-1) + if (p_size == SIZE_MAX) return __underlying_strcat(p, q); if (strlcat(p, q, p_size) >= p_size) fortify_panic(__func__); @@ -110,7 +111,7 @@ __FORTIFY_INLINE __kernel_size_t strnlen(const char * const POS p, __kernel_size size_t ret;
/* We can take compile-time actions when maxlen is const. */ - if (__builtin_constant_p(maxlen) && p_len != (size_t)-1) { + if (__builtin_constant_p(maxlen) && p_len != SIZE_MAX) { /* If p is const, we can use its compile-time-known len. */ if (maxlen >= p_size) return p_len; @@ -138,7 +139,7 @@ __kernel_size_t __fortify_strlen(const char * const POS p) size_t p_size = __builtin_object_size(p, 1);
/* Give up if we don't know how large p is. */ - if (p_size == (size_t)-1) + if (p_size == SIZE_MAX) return __underlying_strlen(p); ret = strnlen(p, p_size); if (p_size <= ret) @@ -155,7 +156,7 @@ __FORTIFY_INLINE size_t strlcpy(char * const POS p, const char * const POS q, si size_t q_len; /* Full count of source string length. */ size_t len; /* Count of characters going into destination. */
- if (p_size == (size_t)-1 && q_size == (size_t)-1) + if (p_size == SIZE_MAX && q_size == SIZE_MAX) return __real_strlcpy(p, q, size); q_len = strlen(q); len = (q_len >= size) ? size - 1 : q_len; @@ -183,7 +184,7 @@ __FORTIFY_INLINE ssize_t strscpy(char * const POS p, const char * const POS q, s size_t q_size = __builtin_object_size(q, 1);
/* If we cannot get size of p and q default to call strscpy. */ - if (p_size == (size_t) -1 && q_size == (size_t) -1) + if (p_size == SIZE_MAX && q_size == SIZE_MAX) return __real_strscpy(p, q, size);
/* @@ -228,7 +229,7 @@ char *strncat(char * const POS p, const char * const POS q, __kernel_size_t coun size_t p_size = __builtin_object_size(p, 1); size_t q_size = __builtin_object_size(q, 1);
- if (p_size == (size_t)-1 && q_size == (size_t)-1) + if (p_size == SIZE_MAX && q_size == SIZE_MAX) return __underlying_strncat(p, q, count); p_len = strlen(p); copy_len = strnlen(q, count); @@ -269,10 +270,10 @@ __FORTIFY_INLINE void fortify_memset_chk(__kernel_size_t size, /* * Always stop accesses beyond the struct that contains the * field, when the buffer's remaining size is known. - * (The -1 test is to optimize away checks where the buffer + * (The SIZE_MAX test is to optimize away checks where the buffer * lengths are unknown.) */ - if (p_size != (size_t)(-1) && p_size < size) + if (p_size != SIZE_MAX && p_size < size) fortify_panic("memset"); }
@@ -363,11 +364,11 @@ __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size, /* * Always stop accesses beyond the struct that contains the * field, when the buffer's remaining size is known. - * (The -1 test is to optimize away checks where the buffer + * (The SIZE_MAX test is to optimize away checks where the buffer * lengths are unknown.) */ - if ((p_size != (size_t)(-1) && p_size < size) || - (q_size != (size_t)(-1) && q_size < size)) + if ((p_size != SIZE_MAX && p_size < size) || + (q_size != SIZE_MAX && q_size < size)) fortify_panic(func); }
@@ -466,7 +467,7 @@ char *strcpy(char * const POS p, const char * const POS q) size_t size;
/* If neither buffer size is known, immediately give up. */ - if (p_size == (size_t)-1 && q_size == (size_t)-1) + if (p_size == SIZE_MAX && q_size == SIZE_MAX) return __underlying_strcpy(p, q); size = strlen(q) + 1; /* Compile-time check for const size overflow. */